The present invention relates to disc storage systems of the type used to store information. More specifically, the invention relates to the interface between slider and a surface of a storage disc.
Magnetic disc drives are used to store magnetically encoded information. As the magnetic disc spins, a transducing head "flies" over the surface of the disc. The transducing head is used to sense magnetic fields from the disc surface during readback of information, and to generate magnetic fields which are impressed onto the surface of the disc during writing of information. As the disc spins, the transducing head is supported by an "air bearing" which is formed between the disc surface and an air bearing slider of the transducer head assembly. The slider body has aerodynamic properties which provide a lifting force.
It is known that improved magnetic interaction between the disc surface and the transducing head can be achieved by reducing the spacing between the head slider and the disc surface. However, as the spacing between slider and disc is reduced, it becomes critical that the fly height be accurately maintained. If the slider should dip slightly, it will touch the surface of the disc and potentially damage the surface. This is particularly problematic with magnetoresistive or magneto-optic recording heads in which contact with an asperity on the disc surface can generate an error in the readback signal.
One technique for achieving very close spacing between the transducing head and the disc surface is described in U.S. Pat. No. 5,550,691 which issued Aug. 27, 1996 to Hamilton and is entitled "SIZE-INDEPENDENT, RIGID-DISK, MAGNETIC, DIGITAL-INFORMATION STORAGE SYSTEM WITH LOCALIZED READ/WRITE ENHANCEMENTS. The Hamilton reference describes a slider for contact recording in which the surface of the slider is dragged across the disc surface.